Fluid-holding containers are often used in vehicle service centers to store and dispense motor oils, transmission fluids, cleaning fluids, gasoline, and other fluids commonly used in or on motor vehicles. Unfortunately, such containers are typically large and bulky and therefore take up too much space, especially for vehicle service centers, which are often small, require multiple containers for multiple different types of vehicle fluids, and are often already crowded with vehicles, service equipment, vehicle parts, etc. Compounding this problem, many conventional fluid holding containers cannot be safely stacked to lessen their floor space requirements because the weight of their contained fluids places too much stress on the lowermost containers, occasionally causing them to buckle and even break. Some fluid-holding containers are designed to be stacked, but doing so can be dangerous, because the stacked containers may tip over when bumped by people or vehicles.